How Do I Fix a Blown Car Amplifier (AMP)

Alex Clarkson
Alex Clarkson

Few things are more annoying than taking a long drive without a working car stereo. Just imagine trying to play music from your car stereo, and it goes silent. The AMP is working, but there’s no sound coming from the speakers, even with the increased volume. Luckily, you can fix the blown car AMP yourself.

You may think that fixing a car AMP requires a great deal of technical expertise, and in some cases, it actually does. But for the most part, the AMP stops working due to a faulty fuse or a bad connection with other components. And these types of issues are easily fixed, even with limited technical expertise and equipment.

playing music on car stereo

Today’s article addresses the issues of blown car AMPs and answers the question of how to fix a blown car amplifier. We’ll describe the entire process step-by-step and provide additional advice and guidelines on how to fix a blown car AMP. So, let’s get started.

How do I fix a blown car amplifier?

Let’s be honest: car amplifiers are complex devices made of hundreds of components that work together to play music in your car. What that means is that you can’t actually fix a broken, or otherwise non-working, amplifier without some knowledge of electronics.

But, as we said initially, a blown AMP isn’t always caused by faulty electronics. Sometimes a blown AMP results from a more common issue; one you can resolve yourself without visiting a car service.

Common causes that blow out a car amplifier

A blown car AMP might happen due to various reasons, from mechanical damage to electrical failure, wear and tear, or simply by accident. Here are some common issues that blow out a car amplifier:

  • Faulty power supply wiring and connections
  • Blown cartridge fuses
  • Protect Mode
  • Faulty speakers wiring and connections
  • Faulty electronics inside the amplifier

Most of these causes require very little to no technical expertise, apart from faulty internal electronics. But don’t worry, we’ll dedicate a section to faulty electronics issues and what you should do in those cases.

Things that you will need

Depending on whether your AMP receives no power or has power but outputs no sound, you’ll need the following tools:

  • Screwdriver set (Phillips and flat, slotted)
  • A multimeter – should read V⎓ and Ω (DC voltage and electrical resistance )
  • Wire strippers
  • Nose pliers
  • Combination pliers
  • A soldering iron set
  • Solder and soldering flux

The tools listed above are the necessary tools required to DIY fix a blown car AMP, and it is by no means a comprehensive list. Depending on your level of expertise and the malfunction in question, you might require additional tools to fix a blown car AMP.

5 Steps to fix a blown car amplifier

Before doing any type of work on your car, please turn the car engine off. Your car’s battery will still supply power to the AMP, regardless of your car’s engine being turned off. That said, if the vehicle doesn’t supply the audio system with power, you might want to check the car’s fuse box. Follow these steps to fix a blown car amplifier:

fixing blown car ampifier

Assess the situation

It’s essential to know whether or not your car AMP receives power from the power supply. You can assess this by turning the amplifier on. If the AMP doesn’t turn on, you should locate your vehicle’s fuse box and locate the fuse that protects your car’s audio. Please refer to your car’s user manual for more detail.

Once you located the fuse, remove it and test it with your multimeter. If you don’t have a multimeter, check for burned filaments inside the fuse, indicating that it’s blown. Replace the fuse if necessary. Next, you should check the power supply, and for this, you’ll have to remove the AMP from its housing inside the car’s control board.

Check the cabling connections

Remove the AMP from its housing on the car’s control board using a screwdriver. Most amplifiers are simply pushed inside the control board, though you might need a screwdriver or even a specialized tool for removal. Additionally, you might need combination or nose pliers for this step.

Once the AMP is removed from the car’s control board, you should inspect the cabling and the connection plugs. Loose plugs are a common occurrence, which can cause your AMP to stop working. This is especially true if the power supply plug becomes loose.

While you’re here, you can check the power supply plug using your multimeter (V⎓); it should range between 12-14V. For this, you should make your multimeter measure VDC (V⎓) and not something else; otherwise, you might blow a fuse on your multimeter too. If the power supply works, check your speaker cables.

Sometimes, faulty or cross-wired speaker cables might trigger your AMP’s protect mode, which then shuts sound output. If that is the case, try disconnecting the speakers to see whether the AMP leaves Protect Mode. In case it does, you should check the wiring on your speakers.

Reconnect and secure any loose wiring, and test your AMP. If it still doesn’t work, you might have to dig a bit deeper and open the AMP.

Remove the AMP’s housing

To remove the AMP’s housing, you’ll need a Philips-head or a flat (slotted) screwdriver. However, before you start removing the AMP’s casing, you should remove all cables and wires connect to it. That means you should unplug it from the power supply and disconnect the speakers.

Additionally, you might want to leave the AMP for 3-5 minutes after you’ve removed it from the power supply. If the unit doesn’t work due to faulty electronics, the unit’s capacitors might come under electrical charge. To avoid any damage and injury, you should wait 3-5 minutes before attempting to remove the AMP’s casing.

This will give capacitors enough time to discharge fully, so you can safely remove the housing and look inside the AMP.

Once removed, you can inspect the inside of the housing itself and the AMP’s internal components. One of the things that might cause an issue is having an internal element in direct contact with the housing.

Car audio amplifier components aren’t supposed to touch metal; otherwise, it might cause a short-circuit or intermittent operation. If one of the components came in contact with the metal housing, apply electrical tape to that area.

Inspect the fuses

Your car AMP might have additional fuses inside the housing to protect it from significant malfunctions. These are usually small, cylindrical glass fuses with small metal caps on each end – otherwise known as cartridge fuses.

Remove the fuses from their sockets, inspect them visually, or use a multimeter set to a buzzer. If the fuse works, the multimeter will buzz, and if it’s blown, the instrument will display a number 1 on the screen. Replace any fuses if necessary, and put them back into their designated sockets. Reassemble the AMP and test if it works.

Check other components

If nothing else works, and your AMP still shows no signs of life, you might want to inspect each internal component individually. You should check the components to see whether they’re burnt, blown, or loose.

For those that are familiar with how to use a multimeter, you can additionally check each resistor. If the readings on your multimeter don’t correspond to the resistor’s rating (within 5% variation), that resistor is due for replacement.

Any burnt component should be removed, replaced, and resoldered back onto their corresponding places. The same thing applies to any loose connections and components.

Additional notes:

  • Most people aren’t familiar with how multimeters work and don’t even own one. However, tutorials can teach you how to use a multimeter to check stuff like voltage and electrical resistance.
  • If you’re unfamiliar with soldering techniques but have access to a soldering iron, you can learn the basics of soldering through online tutorials and crash-courses.
  • In case you’re unable to fix your blown car AMP, we recommend you take the device to your local electronics service. Sometimes it’s simply faulty electronics, and without a certain degree of expertise, fixing the AMP might be out of your hands.

Note: If you are still not able to fix your car’s Amplifier, then its time to buy a ​New Stereo Amplifier


These were the necessary steps on how to fix a blown car amplifier. In most cases, the malfunction is caused by a simple blown fuse or a cross-wired speaker. Sure, this guide might feel a bit technical and overwhelming, but with little practice and a significant amount of patience, you might just fix the AMP yourself.

Remember to stay safe and unplug the power supply before handling any internal components. We highly recommend you venture into this project only for as long as you’re comfortable with it. If not, request the help of someone more experienced than you, take the AMP to the repair shop, or contact the manufacturer.

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